Chusetts



No. 624,875. Patented m 9, I899. B. E. SAWYER & w, n. ARNOTT.

SCREW DRIVER. (Application filed Sept. 13, 1898.)

(No Model.)

//v VENTORS .Bargzscde 5221mm D. flzmo W/T/VE SSE S A TTOHNEY'S,

PAT NT 7 OFFICE.

BURNSIDE E. SAWYER AND WILLIAM'D. ARNOTT, OF ATHOL, MASSA- OHUSETTS.

SCREW-DRIVER.

SPECIFICATION forming part of Letters Patent No. 624,875, dated May 9,1899. Application filed September 13,1898. Serial No. 690,842. (Nomodel.)

To all whom it may concern:

Be it known that we, BURNSIDE E. SAWYER and WILLIAM D. ARNOTT, of Athol,in the county of Worcester and State of Massachusetts, have invented anew and Improved Screw-Driver,of which the following is a specification. 1

As is well known, the sides of the blade or point of the ordinaryscrew-driver are beveled, and hence the same is liable to slip out ofthe nick of a screw or to upset the edges of the nick, and thus defaceand injure the screw-head.

We have devised an improvement by which a series of insertible andremovable parallelsided or flat blades made of high-grade or tool steelare provided for one common holder or stock, whereby the followingadvantages are attained:

First. The insertible flat blades are of uni; form thickness andinserted in a holder not necessarily made of tool or high-grade steel.The sides of the blade being parallel and made to fit slots of standardscrews it will not slip out when great strain is put upon it, as in thecase of screw-drivers having the ordi-. nary wedge-shaped point.

Second. In case a blade is broken (which is a very common occurence) anew one can be inserted at a trifling cost, thus putting the tool in itsoriginal condition with but little delay.

Third. A very important point is, as the blade does not project beyondthe face of the stock enough to bottom in the slot in the head of thescrew, the face of the head of the screw rests upon the end of thestock, thereby steadying the tool and enabling it to drive home thescrew straight without danger of its wabbling about or flying off andinjuring any work upon which it is used. Another strong point is thatthe support of the stock is brought down so far on the blade asto'enable a greater strain to be applied without danger of twist- 5 ingor breaking the blade.

In the accompanying drawings, Figure 1 includes a side view of ourimproved screwdriver and a central longitudinal section of the lower endof thestock. Fig. 2 is a section showing the blade inserted in thestock. Fig. 3 is a perspective view showing a modification. Fig. 4includes a side view and section of another modification.

The shank or stock A is provided at its end with a central lengthwisebore a, a transverse hole a at the upper end of said bore, and atransverse slot 0. at the lower end of the same, the said slot beingarranged at right angles to the transverse bore. A blade B, having afiat tapered shank, Fig. 2, is adapted to fit in said bore or. and slotct -that is to say, the

' blade is-essentially T-shaped,the blade proper,

b, fitting the slot a and the shank b fitting the bore a tightly whenthe device is forced up into place, as shown in Fig. 2. proper, 1),projects from the stock A suificiently to adapt it to enter a nick inthe head of a screw, but it is not intended it shall reach quite to thebottom of the nick, and hence it cannot jam therein.

upper end of the bore a that a. suitable tool may be inserted thereinforthe purpose of forcing out the blade B when required.

In Fig. 4 the stock A is provided with a .vertical slot a in place ofthe transverse hole before described. The said slot 0. is cut in theside of the stock lengthwise and extends inward, so as to communicatewith the bore, as shown. The said slot permits the insertion of a toolfor ejecting the blade.

In Fig. 3 we show a modification in which the slot A is constructed, asin Figs. 1, 3,and 4, save that the longitudinal bore is enlarged toadapt it to receive a cylindrical pin biwhich is split or slottedlongitudinally more than half its length.

The bladeB may be T-shaped,-as before stated, or it may be constructedwithout a shank, as shown at B In either case the blade is inserted andheld in the slot of the pin b, as shown, and said pin being forced Theblade The transverse hole a is so'located. at the I up into the bore inthe stock A its spring-jaws cient to expose the end of it, so that itmay be IO are caused to clamp the blade firmly, so that loosened orejected from said bore, all pracit is held with due security. tically asshown and described.

What We clan 1S BURNSIDE E. SAWYER.

A screw-driver comprisinga stock, the end T r of Which is slotted, acentral bore in said end WILLIAM OT afiording an annular bearing, aT-shaped Witnesses: blade which fits tightly into said bore and T DENNISCOLLINS, slot, an orifice at the end of such blade suffi- ANDREW J.HAMILTON;

